vbd->callback = tapdisk_vbd_callback;
vbd->argument = vbd;
+ INIT_LIST_HEAD(&vbd->driver_stack);
INIT_LIST_HEAD(&vbd->images);
INIT_LIST_HEAD(&vbd->new_requests);
INIT_LIST_HEAD(&vbd->pending_requests);
goto out;
}
-static int
-__tapdisk_vbd_open_vdi(td_vbd_t *vbd, td_flag_t extra_flags)
+/* TODO: ugh, lets not call it parent info... */
+static struct list_head *
+tapdisk_vbd_open_level(td_vbd_t *vbd, char* params, int driver_type, td_disk_info_t *parent_info, td_flag_t flags)
{
- char *file;
- int err, type;
- td_flag_t flags;
+ char *name;
+ int type, err;
+ td_image_t *image;
td_disk_id_t id;
- td_image_t *image, *tmp;
- struct tfilter *filter = NULL;
+ struct list_head *images;
+ td_driver_t *driver;
- err = tapdisk_vbd_reactivate_volumes(vbd, 0);
- if (err)
- return err;
+ images = calloc(1, sizeof(struct list_head));
+ INIT_LIST_HEAD(images);
- flags = (vbd->flags & ~TD_OPEN_SHAREABLE) | extra_flags;
- file = vbd->name;
- type = vbd->type;
+ name = params;
+ type = driver_type;
for (;;) {
err = -ENOMEM;
- image = tapdisk_image_allocate(file, type,
+ image = tapdisk_image_allocate(name, type,
vbd->storage, flags, vbd);
- if (file != vbd->name) {
- free(file);
- file = NULL;
+ /* free 'name' if it was created by td_get_parent_id() */
+ if (name != params) {
+ free(name);
+ name = NULL;
}
if (!image)
- goto fail;
+ return NULL;
+
+
+ /* We have to do this to set the driver info for child drivers. this conflicts with td_open */
+ driver = image->driver;
+ if (!driver) {
+ driver = tapdisk_driver_allocate(image->type,
+ image->name,
+ image->flags,
+ image->storage);
+ if (!driver)
+ return NULL;
+ }
+ /* the image has a driver, set the info and driver */
+ image->driver = driver;
+ image->info = driver->info;
+
+ /* XXX: we don't touch driver->refcount, broken? */
+ /* XXX: we've replicated about 90% of td_open() gross! */
+ /* XXX: this breaks if a driver modifies its info within a layer */
+
+ /* if the parent info is set, pass it to the child */
+ if(parent_info)
+ {
+ image->driver->info = *parent_info;
+ }
err = td_load(image);
if (err) {
if (err != -ENODEV)
- goto fail;
+ return NULL;
err = td_open(image);
if (err)
- goto fail;
+ return NULL;
}
+ /* TODO: non-sink drivers that don't care about their child
+ * currently return EINVAL. Could return TD_PARENT_OK or
+ * TD_ANY_PARENT */
+
err = td_get_parent_id(image, &id);
- if (err && err != TD_NO_PARENT) {
+ if (err && (err != TD_NO_PARENT && err != -EINVAL)) {
td_close(image);
- goto fail;
+ return NULL;
}
if (!image->storage)
image->storage = vbd->storage;
- tapdisk_vbd_add_image(vbd, image);
+ /* add this image to the end of the list */
+ list_add_tail(&image->next, images);
+
image = NULL;
- if (err == TD_NO_PARENT)
+ /* if the image does not have a parent we return the
+ * list of images generated by this level of the stack */
+ if (err == TD_NO_PARENT || err == -EINVAL)
break;
- file = id.name;
+ name = id.name;
type = id.drivertype;
+#if 0
+ /* catch this by validate, not here */
flags |= (TD_OPEN_RDONLY | TD_OPEN_SHAREABLE);
+#endif
+ }
+ return images;
+}
+
+static int
+__tapdisk_vbd_open_vdi(td_vbd_t *vbd, td_flag_t extra_flags)
+{
+ char *file;
+ int err, type;
+ td_flag_t flags;
+ td_disk_id_t id;
+ td_image_t *tmp;
+ struct tfilter *filter = NULL;
+ td_vbd_driver_info_t *driver_info;
+ struct list_head *images;
+ td_disk_info_t *parent_info = NULL;
+
+ err = tapdisk_vbd_reactivate_volumes(vbd, 0);
+ if (err)
+ return err;
+
+ flags = (vbd->flags & ~TD_OPEN_SHAREABLE) | extra_flags;
+
+ /* loop on each user specified driver.
+ * NOTE: driver_info is in reverse order. That is, the first
+ * item is the 'parent' or 'sink' driver */
+ list_for_each_entry(driver_info, &vbd->driver_stack, next) {
+ file = driver_info->params;
+ type = driver_info->type;
+ images = tapdisk_vbd_open_level(vbd, file, type, parent_info, flags);
+ if (!images)
+ return -EINVAL;
+
+ /* after each loop, append the created stack to the result stack */
+ list_splice(images, &vbd->images);
+ free(images);
+
+ /* set the parent_info to the first diskinfo on the stack */
+ tmp = tapdisk_vbd_first_image(vbd);
+ parent_info = &tmp->info;
}
if (td_flag_test(vbd->flags, TD_OPEN_LOG_DIRTY)) {
return 0;
fail:
+
+/* TODO: loop over vbd to free images? maybe do that in vbd_close_vdi */
+#if 0
if (image)
tapdisk_image_free(image);
+#endif
+ /* TODO: handle partial stack creation? */
tapdisk_vbd_close_vdi(vbd);
return err;
}
+/* this populates a vbd type based on path */
+int
+tapdisk_vbd_parse_stack(td_vbd_t *vbd, const char *path)
+{
+ int err;
+ char *params, *driver_str;
+ td_vbd_driver_info_t *driver;
+
+ /* make a copy of path */
+ /* TODO: check against MAX_NAME_LEM ? */
+ err = tapdisk_namedup(¶ms, path);
+ if(err)
+ goto error;
+
+
+ /* tokenize params based on pipe '|' */
+ driver_str = strtok(params, "|");
+ while(driver_str != NULL)
+ {
+ /* parse driver info and add to vbd */
+ driver = calloc(1, sizeof(td_vbd_driver_info_t));
+ INIT_LIST_HEAD(&driver->next);
+ err = tapdisk_parse_disk_type(driver_str, &driver->params, &driver->type);
+ if(err)
+ goto error;
+
+ /* build the list backwards as the last driver will be the first
+ * driver to open in the stack */
+ list_add(&driver->next, &vbd->driver_stack);
+
+ /* get next driver string */
+ driver_str = strtok(NULL, "|");
+ }
+
+ return 0;
+
+ /* error: free any driver_info's and params */
+ error:
+ while(!list_empty(&vbd->driver_stack)) {
+ driver = list_entry(vbd->driver_stack.next, td_vbd_driver_info_t, next);
+ list_del(&driver->next);
+ free(driver);
+ }
+
+ return err;
+}
+
+/* NOTE: driver type, etc. must be set */
+static int
+tapdisk_vbd_open_stack(td_vbd_t *vbd, uint16_t storage, td_flag_t flags)
+{
+ int i, err;
+
+ vbd->flags = flags;
+ vbd->storage = storage;
+
+ for (i = 0; i < TD_VBD_EIO_RETRIES; i++) {
+ err = __tapdisk_vbd_open_vdi(vbd, 0);
+ if (err != -EIO)
+ break;
+
+ sleep(TD_VBD_EIO_SLEEP);
+ }
+ if (err)
+ goto fail;
+
+ return 0;
+
+ fail:
+ return err;
+}
+
int
tapdisk_vbd_open_vdi(td_vbd_t *vbd, const char *path,
uint16_t drivertype, uint16_t storage, td_flag_t flags)
{
int err;
- err = tapdisk_vbd_open_vdi(vbd, name, type, storage, flags);
+ err = tapdisk_vbd_open_stack(vbd, storage, flags);
if (err)
goto out;
projects / xen.git / commitdiff